At present, in order to facilitate people's life, some display devices are manufactured to have a transparent state when displaying (i.e., a transparent display state), so that viewers can see the scene behind the display device. More commonly, this kind of display device can be used in places where physical objects behind the display device need to be displayed, such as show windows, refrigerator doors, etc.
Organic Light Emitting Diode (OLED) devices have attracted wide attention, owing to the advantages of self-luminescence, rich colour, fast response, wide viewing angle, light weight, thin thickness, low power consumption and being realized as a flexible display. Researchers aspire to apply OLED components to display devices that can be manufactured to have a transparent display state, so as to develop an OLED display device that can not only display but also can have a transparent state.